Up-frameshift protein 1 (Upf1) is required for nonsense mediated mRNA decay (NMD) across eukaryotes. It has been reported that Upf1 has also nuclear functions, which are independent of its role in NMD. However, it is unclear whether the nuclear role of Upf1 in mammalian cells is conserved in \(Schizosaccharomyces\) \(pombe\) (\(S\). \(pombe\)). In this study, I investigated whether Upf1 functions in the nucleus and its other possible roles in \(S\). \(pombe\). Similar to the previous findings in mammalian cells, I found that \(upf1\) deletion mutant of \(S\). \(pombe\) was hypersensitive to the DNA replication inhibitors hydroxyurea and methyl methanesulfonate, suggesting increased DNA damage in this mutant. Additionally, each of \(upf1\), \(upf2\) and \(upf3\) shows synthetic sick with \(rad52\), which plays a central role in DNA double-strand break repair in \(S\). \(pombe\). Moreover, the S-phase progression is slower in NMD mutants. I also found an RNA dependent association of Upf1 with highly transcribed genes by chromatin immunoprecipitation (ChIP) experiments, implying its association with nascent RNA. Furthermore, deletion of Upf1 leads to increased RNA levels of \(tf2\) and rDNA, which are bound by Upf1, suggesting it has a direct role in regulating transcription. This hypothesis will be assessed for investigating whether the loading pattern of RNA polymerase II on chromatin changes without Upf1 using ChIP-Seq. Additionally, I identified that Upf1 interacts with genes involved in nuclear activities including nucleosome remodelling, transcription and cell cycle regulation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:685381 |
| Date | January 2016 |
| Creators | Wang, Jianming |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/6657/ |
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